58 ME. F. DEBENHAM ON A NEW [vol. 1XXV, 



A few miles farther on, at the head of the rounded cape of 

 floating ice in the middle of the Sound (D), Ave found that the 

 sponge-spicules were so thickly strewn in the ice that it was 

 impossible to get ice for cooking-purposes that was free of them. 

 There were also fragments of other shelly organisms scattered in 

 the silt of the thaw- water channels. These were for the greater 

 part transported by wind or water, and were much more broken 

 than in the other cases, but they bear testimoiry to the enormous 

 amount of the material that must be scattered over and in the 

 ice between this point and the volcanic islands south of it. 



At Hut Point we found matted tangles of sponge-spicules, as 

 described by Prof. Edgeworth David & Mr. Priestley. The 

 locality is marked (B), but there was no definite deposit, and 

 the specimens were picked np at various points on the low-lying 

 ground. It does not seem likely that these were blown from 

 the direction of White Island, so there is probably a deposit 

 somewhere on the slopes of Observation Hill, similar to those at 

 Cape Poyds. 



Unfortunately, I was not able to visit the region where there 

 seems to be the greatest extent of the raised deposits, in the bay 

 between Black and White Islands, so nothing can be added to 

 Mr. Ferrar's description of them. I was, however, able to see 

 the occurrences at Cape Poyds, in company with Mr. R. E. 

 Priestley, who found them in 1908. 



As described in the memoir by David & Priestley, the two 

 deposits of marine muds lie at a height of about 160 feet above 

 the present level of the sea, and consist of a mixture of mud, 

 small fragments of lava, and the usual assortment of Serpulce, 

 polyzoa, etc. 



Although the greater part of the shell} 7 " material was in small 

 fragments, some of it was very delicate and broke readily in the 

 hand when freed from its matrix. We made a thorough investi- 

 gation of the deposit at Backdoor Bay, and found that it was 

 resting on ice which was proved to be more than a foot thick, and 

 was perfectly clear and free from bubbles, like old glacier-ice. It 

 anay equally well have been sea-ice, from which the salts and the 

 original structure had long since disappeared. Although at so 

 great a height above the sea, these two occurrences fall exactly 

 into line with the others, in that they also are resting on ice. 



Besides the new deposits found in McMurdo Sound, an im- 

 portant corroboration of Prof. David's discovery in lat. 75 c S. 

 -vvas made by his former colleague, Mr. R. E. Priestley. During 

 their enforced stay at Evans Coves during 1912 our Northern 

 Party made several discoveries of raised marine muds, of which 

 Mr. Priestley has kindly given me the following particulars :— 



They were all close to the sea on the surface of the floating ice- 

 sheet which connects Inexpressible Island to the spur of land 

 running south from Mount Abbott. They were about 20 feet 

 .above sea-level, and occurred in patches and low mounds, sometimes 

 mixed with big boulders and sometimes by themselves. With 



